Printing workshop We must have seen the cute little card that comes with the food packaging? Tilt the card or move the card back and forth to see all sorts of fantastic effects. These plastic cards are the lenticular prints we are familiar with. Today, printers are using lenticular lens printing processes to obtain more complex products, ranging from labels, poster posters to packaging products, and even plastic cups. Although we do not see stereoscopic visual effects in the true sense, but merely visual deception, raster printing is not just a small game for children. It has very broad prospects for development. According to Mike Chadwick, production manager at KBA's Karat 74 direct imaging press, raster printing is no longer as complex as it used to be. In the past, people viewed raster printing as a mystical technique. With the development of new software and the development of printing machines and other process technologies, raster printing has gradually become the mainstream of the printing industry. Chadwick also reminded everyone that despite technical and software support, raster printing is still a very demanding technology. If the printer does not understand the principle of raster printing, then we are just like playing a rowing boat and letting the rowing boat do the trick. Compared with plastic printing, lenticular printing is more costly, more complex and more sensitive to technology and prepress technology requirements more profound. The singular visual effect of raster printing is obtained by combining digitally integrated images with ribbed plastic gratings. The key steps in production include interlacing software to process the image, requiring the computer to have sufficient processing power to process the scanned image file, the data volume of such files is generally large), the plastic grating plate forming technology, and prepress and printing The accuracy of the equipment. The special place of grating If you study grating materials carefully, you will find that printing grating products will face more challenges. According to the Lenstar organization (an organization that provides online resources for designers, agents, and printers), one side of an extruded plastic grating is a small wrinkled corrugation called a small grating; the other side is smooth. On the printed surface. The same size cylindrical grating covers the entire surface evenly with a resolution of 10-200 lines/inch, depending on the application. The grating thickness is between 0.008 to 0.385 inches. Printing on lenticular materials also has the same challenge as plastic printing: lenticular printing is more expensive than printing on paper. If the environment is not controlled, the plastic will shrink or expand and deform. Moreover, plastics are non-porous materials, and the ink printed on them is difficult to penetrate and only stays on the surface. Therefore, unless you use UV printing or other drying methods, the production process will be longer. Although we can use traditional printing methods to print grating products, many experts agree that UV printing will be easier to implement. John Santie, director of production for Mitsubishi offset offset press in the United States, said: "We believe that UV printing will have a stronger advantage in terms of dryness and the substrate's absorbability." Companies investing in raster printing should have UVs. Printing experience, otherwise it is asking for trouble. What is the customer wants Santie also added that the real challenge in the field of raster printing is color separation. The printing staff should be trained to understand what kind of product is a good product and learn how to figure out what the customer really needs. He explained that the final result of the print determines what kind of printing method printers should use. Or, how to select the screen resolution or the resolution on the reticle, and finally achieve the desired image quality. Raster printing requires more precise registration than plastic prints — otherwise, it cannot exhibit special effects. An article in a recent issue of Heidelberg News stated that the stereoscopic effect of a grating is obtained by separating and recombining the image into a fine grating. Therefore, if the paper is overprinted, even if it is a slight deviation, the product will become a waste product. Even the smallest gap can affect the effect of the entire layout. Since the operation of the printing cylinder differs depending on the printing machine and different printing units on the same printing press, all these differences will not affect the traditional printing work and can be ignored. However, this is true for raster printing. is very important. If some pixels on the reticle deviate, this error will be apparent. For example, imagine if the magenta version of a print containing a person's face is not registered, even if the magenta version is slightly more prominent than the other plates, when the pattern changes, you will see it first To magenta, this picture became a waste product. Therefore, the production of raster prints requires very high precision. Klenke used the Heidelberg Speedmaster SM 52 to print raster jobs. Klenke, who is responsible for the company, said that the continuous improvement of the small format printer has achieved satisfactory "accuracy requirements." Small format printers print more cleanly and with higher precision and can produce high quality products. National Graphics (Brookfield, WI), a raster printing company with multiple raster and lithographic printing patents, Don Krause, the company’s manager, stressed the importance of properly aligning the lens with the lens. There can be no deviation - the image should have the appropriate resolution, correspond to the resolution of the grating, and also match the viewing distance of the human eye. Whether it's making small, hand-held cards, posters, or surface materials used to wrap other products, there are many techniques involved, not just the simple matter of spreading ink onto plastic. Direct imaging (DI) printers are also a viable alternative to lenticular printing. At the Drupa 2004 exhibition, Presstek introduced ProFire Excel image processing technology to enable DI printers to print up to 300 lpi prints. The higher registration accuracy, combined with the short print-to-live preparation time of DI printers, makes DI printers the best choice for printing on hundreds to thousands of raster prints. Stephen Sanker, press sales manager for DI presses in North America, says that the advantages of DI presses are the registration and rapid drying speeds of the single cartridge. Digispec's high-quality and beautiful mouse pad H&H Enterprises (Las Vegas) is one of the largest manufacturers of mouse pad in the United States. In 2003, the company installed the Speedmaster CD-74 equipped with a UV device, which is the first North American company in Heidelberg. In the past, the company's products were printed on paper and then processed using three laminators that worked 16 hours a day. Since they owned the CD-74 press, they have reduced the drying time of the ink, thus enabling the task of printing directly on plastic. The company's name is now Digispec. Recently, the company won the Gold Award for PPAI Achievements for its ability to apply 3D flip effects to the production of mouse pads. Digispec originally used the Heidelberg CD-74 UV printer to print plastic products. Two years ago, the company expanded its business to lenticular printing, with a capacity of more than 125 prints. At the same time, they also use their own software developed to print Pacur and VPI gratings. Monique Favreau, sales manager, said that the precision of their printed products was higher than any of the products he had seen. The secret is to pay more attention to the selected picture itself rather than blindly increasing the depth of field, otherwise it will ruin the effect of the entire print. Lithographix: Seven Years of Raster Printing Lithographix has used the 40-inch format Mitsubishi printing press to print its grating business for nearly seven years. The company has two production plants in Los Angeles and Carlsbad, which are engaged in film, automotive retail, apparel agency, and raster printing. The company mainly prints orders for Dodge baseball cards, signage, and the NFL (National Football League). The product size is 20 x 28 inches, the resolution is 300 lpi, the length of the printing plate is from 1000 to 20,000, even can reach 50,000. The company's production manager, George Wolden, told us that raster printing requires very precise registration and that the image files are also large. In the printing process, the color and the split file must be controlled and managed, and the image and the raster plate must be accurately attached together. Wolden also told us that the lacquer printing brought us the test throughout the entire printing shop. Many salespeople and printers boast about their products but do not understand the technical parameters and do not understand how the gratings are extruded. Raster printing also requires proofing and complicated printing checks. Universal Lithographers: Accurate Feed Feed Registration The caption of Universal Lithographers (Sheboygan, WI) is: We can help you print anything that you can imagine. The company relies on two six-color manroland 706 presses with on-line coating equipment. Universal Lithographers has been around for 42 years, and Deputy General Manager Jerry Keller said: “Our company does not use UV technology, but we use infrared to dry it. This method is also very good.†Through professional multi-color printing production, Universal's sales climbed to 6 million US dollars. The application scope of raster printing includes promotional products such as POP point-of-sale advertising and POS point-of-sale services. At present, the company uses Photoshop as an interlaced scanning software. This work is very laborious, so the company is currently evaluating professional software for testing raster printing. Roland 700's vacuum table and pneumatic side gauge are ideal for raster printing. At a press speed of 12,000 sph, the grating plate will reduce its speed by 65% ​​when it hits the front rail. Unlike other brands of presses, which use rollers to correct the positioning of the paper, Roland 700 has a suction pad under the paper that pulls the reticle upright without leaving any traces. Feeder registration is very important for lenticular printing. Keller told us that Roland 700's grating plate feed handling capability and conveyors are excellent for this work. Blanks Printing: DI Shows Skills In September 2004, Blanks Printing & Imaging (Dallas) of Texas, USA introduced the first KBA 74 Karat press. Blanks was previously a prepress company with a 90,000 square foot facility and two fully open Heidelberg presses. The 29-inch Karat direct-imaging press is capable of performing plastic printing jobs, and with its short-lived preparation time, the company has helped the company gain a foothold in the 40-inch format. Before trying raster printing, the company did some plastic printing business. Their first raster print, the calendar, was produced very smoothly. Kevin Schrader, Blank's Vice President, praised: "The KBA 74 Karat has run very smoothly. Our first raster print is a picture of one picture, one picture and one dark picture. We didn't think we would have a good effect. However, after the printing on the machine, the brightness and darkness compensation of the two pictures was very appropriate." Schrader thinks that 74 Karat is ideal for lenticular printing. He explained: “The printer's bite teeth do not release until after the process of printing, coating, etc. is completed. This ensures accurate registration. "In addition, the printing press has a shorter preparation time and is more economical than a 40-inch press. More information Some of the companies we have contacted are reluctant to disclose their trade secrets - they have tried hard to explore how to make grating products more perfect and hope to keep their secrets of experience secret. If you want to see a real-world product like the real world, please visit Lenstar.org. In addition, the site also